The University of Southampton
University of Southampton Institutional Repository

Testing and analysis of axial gap permanent magnet DC motors

Testing and analysis of axial gap permanent magnet DC motors
Testing and analysis of axial gap permanent magnet DC motors
This thesis is concerned primarily with the testing and analysis of design variations of the Lynch motor, which is an axial gap permanent magnet dc machine. These variants include: a standard production motor, a motor with low iron volume, a motor with bigger area of magnets and a motor using powder iron instead of laminations. The powder iron motor was constructed by the author, while all the other motors were provided by the Lynch Motor Company.
Tests were conducted to evaluate motor circuit parameters, losses and efficiency using a purpose built test rig which was built in the first stage of the project. Finite element analysis (FEA) was used to determine the levels of the magnetic saturation in the different motors and calculate torque, inductance and EMF. The FEA was also used as bases for comparison with analytical electromagnetic calculations. A dynamic circuit model, whose parametric were derived from FEA and analytical calculations validated by test, was also constructed to study the effect of brush thickness on circulating current and torque production.
The results of the work revealed that the larger magnet motor has a high level of saturation resulting in a higher slope of the torque-speed curve. The lower iron volume motor and the powder iron cored motor produced less torque and have less flux density than the standard Lynch motor. The test results proved that the selected powder iron material is usable in the Lynch rotated armature but it still needs improvements to close the performance gap with laminations. The powder iron motor has back emf that is 10% lower than the standard motor, and consequently a lower efficiency.
The results show that performance of the Lynch motor can be improved by optimising the size of the saturated parts of the motor, which are the stator discs and the armature teeth. In addition, careful selection of brush number, geometry and type can improve the motor performance.
An alternative single gap motor was also studied. The test results show that it has more armature reaction than the dual gap motor and therefore it produced less torque with less efficiency.
Mohammad, Mohammad T.N.
d6305885-4873-4006-ab9f-e23ee47ab64d
Mohammad, Mohammad T.N.
d6305885-4873-4006-ab9f-e23ee47ab64d

Mohammad, Mohammad T.N. (2004) Testing and analysis of axial gap permanent magnet DC motors. University of Southampton, School of Engineering Sciences, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

This thesis is concerned primarily with the testing and analysis of design variations of the Lynch motor, which is an axial gap permanent magnet dc machine. These variants include: a standard production motor, a motor with low iron volume, a motor with bigger area of magnets and a motor using powder iron instead of laminations. The powder iron motor was constructed by the author, while all the other motors were provided by the Lynch Motor Company.
Tests were conducted to evaluate motor circuit parameters, losses and efficiency using a purpose built test rig which was built in the first stage of the project. Finite element analysis (FEA) was used to determine the levels of the magnetic saturation in the different motors and calculate torque, inductance and EMF. The FEA was also used as bases for comparison with analytical electromagnetic calculations. A dynamic circuit model, whose parametric were derived from FEA and analytical calculations validated by test, was also constructed to study the effect of brush thickness on circulating current and torque production.
The results of the work revealed that the larger magnet motor has a high level of saturation resulting in a higher slope of the torque-speed curve. The lower iron volume motor and the powder iron cored motor produced less torque and have less flux density than the standard Lynch motor. The test results proved that the selected powder iron material is usable in the Lynch rotated armature but it still needs improvements to close the performance gap with laminations. The powder iron motor has back emf that is 10% lower than the standard motor, and consequently a lower efficiency.
The results show that performance of the Lynch motor can be improved by optimising the size of the saturated parts of the motor, which are the stator discs and the armature teeth. In addition, careful selection of brush number, geometry and type can improve the motor performance.
An alternative single gap motor was also studied. The test results show that it has more armature reaction than the dual gap motor and therefore it produced less torque with less efficiency.

This record has no associated files available for download.

More information

Published date: 2004
Organisations: University of Southampton

Identifiers

Local EPrints ID: 47955
URI: http://eprints.soton.ac.uk/id/eprint/47955
PURE UUID: b20f2d29-fdf5-4782-8d64-38ff0a6cee90

Catalogue record

Date deposited: 15 Aug 2007
Last modified: 11 Dec 2021 16:45

Export record

Contributors

Author: Mohammad T.N. Mohammad

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×